A 2-bit 3-D-Printed Reflectarray Antenna Using Cylindrical Rotation-Based Phase-Tunable Elements

In this article, a low-cost and mechanically robust approach for the design of mechanically phase-tunable reflectarray (RA) elements operating in the C-band is proposed. The proposed element is composed of an open cylindrical shell made of a nonuniform dielectric material. A 2-bit phase tunability is achieved by implementing mechanical rotation of the open cylindrical shell. The proposed element is fabricated by 3-D-printing technology, and the infill rate of the open cylindrical shell is spatially nonuniform. As a result, the effective relative permittivity of the fabricated open cylindrical shell becomes nonuniform. Phase tunability of the fabricated element is demonstrated numerically and experimentally. An RA antenna composed of the proposed elements is designed and fabricated. It is clarified that the RA antenna demonstrates beam scanning coverage up to 50° while its aperture efficiency is comparable to conventional RA antennas.